Dermatology: Key Skin Lesions and Conditions for Medical Students

Bulla

Large fluid-filled blister greater than 1 cm in diameter.

Clubbing

Enlargement of fingertips with a downward curve of nails, often related to chronic hypoxia.

Confluent

Skin lesions that run together or merge.

Cyanosis

Bluish discoloration of skin or mucous membranes due to lack of oxygen.

Ecchymosis

A bruise; discoloration caused by bleeding under the skin.

Erythema

Redness of the skin due to increased blood flow.

Jaundice

Yellowing of the skin and eyes caused by elevated bilirubin.

Keloid

Thick, raised scar that extends beyond the original wound boundary.

Leukonychia

White spots or streaks on the nails.

Linear

Lesions arranged in a straight line.

Macule

Flat, distinct, discolored spot less than 1 cm in diameter.

Nevi

Commonly called moles; benign pigmented skin lesions.

Nodule

Palpable, solid lesion larger than 1 cm; may extend into deeper skin layers.

Pallor

Paleness of the skin due to decreased blood flow or hemoglobin.

Papule

Small, raised, solid skin lesion less than 1 cm.

Patch

Flat, discolored skin lesion larger than 1 cm.

Petechiae

Small, pinpoint red or purple spots caused by minor bleeding under the skin.

Plaque

Raised, flat-topped lesion greater than 1 cm, often formed by coalescence of papules.

Pustule

Small, elevated, pus-filled lesion.

Rash

General term for skin eruption or outbreak.

Scar

Fibrous tissue replacing normal skin after injury.

Striae

Stretch marks; linear marks from skin stretching and thinning.

Turgor

Skin's elasticity; tested by pinching skin to assess hydration status.

Vesicle

Small, fluid-filled blister less than 1 cm in diameter.

Zosteriform

Lesions arranged in a linear pattern along a nerve route (dermatome), often seen in shingles.